Freescale offers touch-panel software 'absolutely free'

PORTLAND, Ore. -- Frank Zappa made fun of the "absolutely free" concept by selling a full-priced album by that name in 1967. Now, 40 years later, Freescale Semiconductor Inc. (Austin, Texas) is making good on the "absolutely free" offer, with software to create capacitive touch panels and virtual rotary dials. This library of "absolutely-free" touch-panel software was unveiled on the eve of Freescale's Technology Forum (Nov. 28-29, 2007) in Shenzhen, China.

"We are offering complimentary proximity-sensing software as a free download from our Web site," said Kenneth Lenk, consumer and industrial sensors operations manager, sensor and actuator solutions division. "Engineers get the complete source code, which they can modify anyway they please, royalty free."

Touch pads, virtual rotary knobs, sliders--the whole proximity sensor market is estimated to grow from under $2 billion to nearly $4 billion over the next five years, according to Gartner and iSuppli studies cited by Freescale. The free software offered will enable Freescale processor chips to control touch pads and virtual rotary dials. The iPhone integrated a touch-panel with its display, but for inexpensive touch-sensitive control panels using Freescale's software library, the icons and legends that identify buttons and their functions will be stenciled right onto the body of the device, including remote controls, cell phones, appliances and building controls.

Touch sensitivity aims to eliminate the mechanical switches that stud most electronic devices, replacing them with flat, smooth "virtual" buttons that sense the proximity of a finger by the change in capacitance it causes. Unlike touch screens that require special transparent pads to sense the proximity of a finger, the touch pads made possible by Freescale's software require only an etched printed-circuit board covered with plastic. Icons or legends on the device's case indicate the location of the virtual buttons.

Using Freescales's complementary proximity-sensing software, panels with up to 32 touch pads can be monitored with a Freescale S08 or V1 microcontroller. For simpler devices that don't require a microcontroller at all--such as an eight-switch panel--Freescale has designed two chips: the MPR083 emulates an eight-segment rotary dial and the MPR084 manages up to eight separate touch pads. The 20-segment MPR081 (rotary) and the 20-segment MPR082 (touch-pad) were announced earlier this year.